| Popis: |
The preponderance of evidence bearing on the detection of signals in noise indicates that detection takes place after at least a limited (critical‐band) frequency resolution. However, a study reported by Fricke in 1968 suggests that two‐tone octave waveforms are considerably more detectable for certain phase relations of the two components than for others. Such a result is understandable only if one postulates detection of the complex waveform prior to frequency separation. In addition, recent reports of recordings of first‐order auditory neurons indicate that an analog of the complex waveform appears at the first neural coding. The study reported here is essentially a repeat of the Fricke study. For each set of waveforms compared, the energy was kept constant and only the phase relations changed. One set consisted of two equally detectable components; the other, of two components with supposedly equal displacement amplitude at the locus in the cochlea normally maximally responsive to the higher frequency. In neither case was there a difference between waveforms of different phase relation large enough to be attributed to factors other than chance variation. If there are differences in the detectability of two‐tone harmonic signals of the same energy but different waveform, this study indicates they are quite small. |
